Apparatus for transporting blanks through a drying zone



Feb. 20, 1962 WINKLER ETAL APPARATUS FOR TRANSPORTING BLANKS THROUGH ADRYING ZONE 2 Sheets-Sheet 1 Filed Nov. 18, 1958 INVENTORS R/c/mro/Mnk/er and K010 Dunne/er A r roams-r 1962 R. WlNKLER ETAL 3,021,610

APPARATUS FOR TRANSPORTING BLANKS THROUGH A DRYING ZONE Filed Nov. 18,1958 2 Sheets-Sheet 2 1 A m A "o INVENTORS A //'c/)Qrd M'mf/cr a andKara fiu/mebler- BY A MZW 1 v meur v s I states 1 This invention relatesto envelope making machines, and more particularly to an apparatus fortransporting envelope blanks through the drying section thereof to drythe gum on flap portions of the blanks. For example, envelope machineshave a section wherein blanks are lapped one upon another, to leave onlythose portions of the sealing flaps exposed to which the gum is to beapplied by means of a roll applicator in the form of a continuous bandof adhesive. After application of the gum, the blanks are moved slightlyapart to separate the gum on one blank from the gum on the adjacentblanks of the lapped formation. The blanks are then conveyed through adrying zone at the lower portion of the machine, and which usuallyextends from one end thereof to the other. Heretofore, the simplestmethod of conveying the blanks through the drying zone was betweenendless fabric belts, usually of cotton material. The belts werearranged in upper and lower pairs, so that the lower run of the upperbelts cooperated with the upper run of the lower belts to grip the sideflap portions of the blanks therebetween, and a strand was used tosupport the gummed side of the sealing flap portions. The difiicultiesof such an arrange ment are that the fabric belts stretch under tensionand vary in thickness, so that it is impossible to maintain uniform gripon the blanks. Change in spatial relationship of the blanks is notpermissible at high speed. It is obvious that this may lead to seriousjamming in subsequent operating sections of the machine.

Another difiiculty is that the strand which supports the sealing flapsmarks the freshly applied gum. Another difiiculty is that it is verydiificult to run envelopes with short side flaps, using cotton belts. Afurther difiicu-lty is that because of the expense and complication ofsupporting numerous guide rollers, the runs of the belts are allowed totake the form of catenaries. Therefore, to allow room for the belts, theheight of the machine required an operators platform along the length ofthe machine, so that the operator could reach and service the operatingmechanisms at the top of the machine.

Machines of lower height have been constructed by using a single set ofchain belts wherein the links of the chain are provided with clips forsecuring the blanks, but these clips must be used in great number andthey are easily deformed, requiring constant inspection and replacement.They are also apt to mark and damage the blanks.

It is the principal object of the present invention to provide blanktransporting apparatus that eliminates the difiiculties of previousstructures.

Other objects of the invention are to provide means for effecting apositive clamping or gripping action without marking or damaging theblanks; to provide means having such a high coefficient of friction thatit is unnecessary to support the midportions of the blanks during thedrying process; to provide blank carrying means whereby the blanks arecarried in a linear path through the drying section; to provide a blanktransporting means which simplifies the addition of new sections in theenvelope making machine; to provide a blank transporting means of simpleconstruction in which the active runs of the belts are guided by rails;to provide transporting means which hold the blanks gently yet firmly athigh speeds; to provide trated in FIG. 1.

Bfillfil Patented Feb. 20, 1952 transporting means in the form ofrelatively non-stretchable chains; and to provide gripping pads whichare preferably incorporated in the structure of the chains.

In accomplishing these and other objects of the invention as hereinafterpointed out, we have provided improved structure, the preferred form ofwhich is illustrated in the accompanying drawings, wherein:

FIG. 1 is a longitudinal section on the line 1--1 of FIG. 2 of atranportation apparatus for conveying envelope blanks through the dryingzone of an envelope making machine to dry gum on the sealing flapportions of the blanks, the section being shortened to permitillustration thereof ona larger scale.

FIG. 2 is a cross section on the line 2--2 of FIG. 1.

FIG. 3 is a plan view of the lower chain belt and the upper feed anddischarge belts at the ends of the drying section.

FIG. 4 is a fragmentary perspective view of a modified form of the upperchains, which utilizes pads with crowned gripping faces.

FIG. 5 is a perspective view of the end of one of the guide rails.

FIG. 6 is a diagrammatic underneath view of the envelope blanks, onsmaller scale, showing separation of the gum on the sealing flaps.

Referring more in detail to the drawings:

l and 2 designate upper and lower pairs of belts which carry blanks a inoverlapped, slightly stepped formation from a seal flap gumming device(not shown) of an envelope making machine to the drying section 3 of themachine. The belts composing each pair of belts are spaced apart toengage the end flap portions b and c of the blanks a with the gum on thesealing flap portions facing outwardly and downwardly at the deliveryends of the belts. At the delivery ends of the belts, the belts 1 havesubstantially horizontal runs 4 that cooperate with correspondinghorizontal runs 5 of the outer belts 2 to carry the blanks a inalignment with the path of the blanks through the drying section 3, aslater described.

The horizontal runs 5 are longer than the horizontal runs 4 and areguided over rollers 6. Rollers '7 which guide the horizontal runs 4 are,therefore, offset from the rollers 6 for accommodating pressure rollers8 to facilitate delivery of the blanks at the same speed and lappedrelation as during application of the gum to the sealing flaps.

In order to separate the gum on the respective blanks, the blanks mustbe slightly separated prior to their passage through the drying zone.This is effected by rollers 9 and it) that operate at a higher surfacespeed than the pressure rollers 8. The blanks are removed from thedrying section between belts 11 and 12 and a center belt 13 that carrythe blanks to the sections of the machine where the blanks are convertedinto envelopes.

The structure thus far described is substantially conventional andspecifically forms no part of the present invention, the presentinvention pertaining primarily to an apparatus for transporting orconveying the blanks through the drying section 3 and the combinationtherewith of the mechanisms thatcarry the blanks to and from the dryingsection, as now to be described.

The apparatus for conveying the blanks through the drying section isgenerally designated 14 and comprises a lower pair of endless chains 15and 16 that operate over pairs of sprockets 17 and 18 carried by shafts19 and 2!) at the respective ends of the drying section 3, as bestillus- "ihe transporting apparatus also includes an upper pair of chains21 and 22 operating over pairs of sprockets 23 and 24 carried on shafts25 and 2rd inset from the shafts l9 and 26, whereby the upper chains 21and 22 are of shorter length than the lower chains 15 and 16 to providespaces at the ends of the lower chains for feed or guide rollers 27 and28 to facilitate entrance and exit of the blanks a to and fromengagement with the upper and lower chains 15-16 and 21-22.

The chains 15-16 and 2122 are of substantially the same construction, inthat they include side links 29 of ordinary construction that connectlinks 30 of a form to carry gripping elements 31. The links 3% havesides 32 and 33 interconnected by webs 34 (FIG. 4) to carry the grippingelements 31. The gripping elements 31 are fixed to the webs, for exampleby vulcanizing them to the webs 34. The links are interconnected bytransverse pins 35 carrying rollers 36 substantially corresponding tothe pins and rollers of conventional roller type chains. (The grippingelements 31 comprise resilient blocks or pads 37 of a rubber or similarsynthetic material that does not mark the blanks a when the blanks areengaged thereby.

The pads 37 have base portions 38 of a width and length substantiallycorresponding to the webs 34 and preferably outwardly converging sides39 and 40 joining with contact faces 41. The ends 42 and 43 of theblocks or pads may extend at right angles from the plane of the baseportions 38 to provide clearance 44 between the respective blocks orpads when the links are connected together by the pins 35. The faces 41of the blocks of the upper chains 21-22 may be slightly crowned in thelongitudinal direction of the chains, as shown in FIG. 4, but the padsof the lower chains are preferably hat, to constitute linear supportsfor the side flap portions b and c of the blanks a when engaged by thepads of the upper chains.

When the chains are mounted on the pairs of sprockets 17-18 and 23 24,the lower runs 45 of the upper chains and the upper runs 46 of the lowerchains are in registry and are retained in linear paths by pairs ofguide rails 47 and 48. The guide rails 47 and 48 are preferably ofchannel cross section to provide side flanges 49 and t and a web 51having a width to accommodate the links of chains therebetween, as bestshown in FIG. 2, and the midportions of the webs have longitudinal ribsor tracks 52 for contact by the rollers 36 of the chains, whereby thefrictional contact faces 41 of the resilient pads are supported inlinear alignment substantially along the length of the guide rails toprovide substantially equal pressure on the blanks as they are beingcarried through the length of the drying section of the envelope makingmachine.

In order that the guide rails may be as long as possible, the endsthereof are provided with slots 53 in registry with ribs or tracks 52,as best shown in FIGS. 1 and 5, and the ends of the ribs or tracks areshaped to provide ramps 54 to facilitate contact of the rollers with theribs or tracks as the links with the pads move around the sprockets andonto the tracks. In order to facilitate entrance of the blanks betweenthe pads of the chains and exit of the blanks therefrom, the guide rails47 supporting the upper runs of the lower belts are preferably supportedat heights relative to the axis of the sprocket shafts, so that as theblocks approach the end of the guide rails and the rollers move up theramps at the forward end of the guide rails, the contact faces 41 of thelower pads are preferably tilted at a slight angle, as indicated at 55,FIG. 1, and so that the pads, as they leave the ends of the guide rails,move away from contact with the blanks and thereby avoid any possibilityof marking the blanks.

The upper guide rails 48 are resiliently backed by springs 56 to pressthe pads on the lower run of the upper chains into contact with theblanks, to cooperate with the lower pads in gripping the blankstherebetween and carrying the blanks firmly through the drying section.The lower rails 47 are rigidly supported on brackets 57 carried bysupports '58 that extend laterally and which are in turn carried bybrackets 5? having internally threaded sleeve portions 60 carried onthreaded portions 61 on a transverse shaft 62. The transverse shaft maybe suitably mounted on the side frames of the envelope machine so thatit may be rotated to adjust the guide rails according to the size of theenvelope blanks, it also being understood that the sprockets 17-18 and23-44 are also adjustable on their shafts 19-20 and 25-26, as will beapparent to those skilled in the art of envelope making machines. Thesprings 56 may be backed by arms 63 that are also adjustable with theguide rails.- In order to support the upper runs of the upper chains,the sleeve portions '60 of the main brackets 59 carry laterallyextending shafts 64 mounting idler sprockets 65, as best shown in FIGS.1 and 2. To support the lower runs of the lower chains, the supports 58may carry rollers .66, also shown in FIGS. 1 and 2. It is obvious thatas many of the main supporting brackets and transverse shafts 62 may beused as are necessary to carry the guide rails, idler sprockets 65 androllers 66.

The drying medium used in the drying section of the machine may beheated air that is conducted along the length of the drying zone bymeans of a duct 67 and discharged in contact with the gummed areas ofthe blanks through perforations 68 in the upper portion of the duct, asshown in FIG. 2.

Assuming that the machine is in operation and that one of the sprocketshafts 25 or 26 and 19 or 20 is being driven to actuate the upper andlower pairs of transport chains at the same linear speed through thedrying section, blanks are delivered from the gnmming roll between theruns 4 and 5 of the belts 1 and 2 in lapping fanned relation, as shownat the lefthand side of FIG. 6, with the gum forming a continuous band.Upon contact with the rollers 9 and 10, the blanks are moved apart asshown at the righthand side of FIG. 6, to separate the gum on therespective seal flap portions of the blanks. The blanks are then fedonto the pads on the forward end of the upper run of the lower beltswith the aid of the feed rollers 27. The blanks then enter the spacethat is formed between the horizontal pads on the upper runs of thelower belts and the pads of the upper chains as they move successivelyinto position to form the lower horizontal runs of the upper chains, tocooperate with the pads on the upper runs of the lower chains to gripthe blanks as shown in FIG. 1. With continued movement of the belts, thelinks carrying the pads enter the channel shaped guides with the rollersof the chain bearing in rolling contact with the tracks 52 of the guiderails, so that the pads continue the grip on the blanks and pre vent anyrelative movement thereof during transfer of the blanks through thedrying section. Upon reaching the end of the upper pairs of chains, thelinks carrying the pads move around the sprockets 24 to free the blanks,so that the blanks may be discharged from off the upper run of the lowerchains in cooperation with the feed rollers 23, to feed the blanks underthe lower run of the center belt 13 and between the upper and lowerpairs of offtake belts 12 and 11 respectively to carry the dried blanksto the envelope converting mechanisms of the machine.

From the foregoing, it is obvious that we have provided a substantiallynonstretchable means for transporting the blanks in a linear paththrough the drying zone, and that the lapped blanks are gripped and heldtogether between the pads on the chains so that the blanks cannot shifttheir relative positions during transport through the drying section ofthe envelope making machine. It is also obvious that the rubber padshave a high coefficient of friction, so that the contact faces thereoffirmly grip the blanks to support the gummed portions of the blanks intaut condition across the space between the chains without intermediatesupports that might interfere with the gum or drying thereof.

Another advantage is that blanks of thin and fragile materials may beconveyed without slipping or damage thereto.

What we claim and desire to secure by Letters Patent is:

1. Apparatus for conveying envelope blanks in lapped and slightlystepped relation through a drying section of an envelope making machineto expose gummed portions of the blanks to a drying medium, saidapparatus including a lower pair of endless chains each composed ofinterconnected links, blocks of resilient material carried on said linksand having frictional faces for supporting contact with portions of saidblanks laterally and outwardly of the gummed portions, means forsupportingsaid lower pair of chains to provide upper runs for continuousmovement through said drying section in laterally spaced apart parallelrelation and providing a substantially uninterrupted space between saidupper runs at least corresponding in width to the width of the gummedportions of the blanks for the full length of the drying section forfree access of the drying medium to said blanks, separate longitudinalguide means below each of said upper runs for retaining the frictionalfaces of said blocks in linear alignment for supporting said lateralportions of the blanks thereupon, an upper pair of endless chains havinginterconnected links, similar blocks of resilient material on the linksof the upper chains and having frictional faces for pressing contactwith the lateral portions of the blanks, means for supporting the upperpair of chains in correspondingly spaced apart relation and to providelower runs in registry with and extending longitudinally above the upperruns of the lower chains to operate at the same linear speed, guidemeans for backing said lower runs for pressing the fractional faces ofsaid blocks on the links of the lower runs into contact with theportions of the blanks supported upon the frictional faces of the blockson the links of the upper runs of the lower chains for gripping thelateral portions of the blanks between said frictional faces formaintaining the gummed portions of the blanks in substantially tautcondition across said space solely by the gripping action on saidlateral portions of the blanks while the blanks are being carriedthrough the drying section, and means for delivering the blanks in saidlapped relation onto said frictional faces of the blocks of the upperruns of the lower chains.

2. Apparatus for conveying envelope blanks in lapped and slightlystepped relation through a drying section of an envelope making machineto expose gummed portions of the blanks to a drying medium, saidapparatus including a lower pair of endless chains each composed ofinterconnected links, blocks of resilient material carried on said linksand having frictional faces for supporting contact with portions of saidblanks laterally and outwardly of the gummed portions, means forsupporting said lower pair of chains to provide upper runs for movementthrough said drying section in laterally spaced apart parallel relationand provide a substantially uninterrupted space between said upper runsat least corresponding in width to the width of the gummed portions ofthe blanks for the full length of the drying section for access of thedrying medium to said blanks, separate longitudinal guide means beloweach of said upper runs for retaining the frictional faces of saidblocks in linear alignment for supporting said lateral portions of theblanks thereupon, said longitudinal guide means having forward ends of ashape to tilt the links as the links engage said guide means tofacilitate passage of the blanks onto the frictional faces, an upperpair of endless chains having interconnected links, similar blocks ofresilient material on the links of the upper chains and havingfrictional faces for contact with the lateral portions of the blanks,means for supporting the upper pair of chains in correspondingly spacedapart relation to provide lower runs in registry with and extendinglongitudinally above the upper runs of the lower chains to operate atthe same linear speed, guide means for backing said lower runs forpressing the frictional faces of said blocks on the links of the lowerruns into pressing contact with the portions of the blanks supportedupon the frictional faces of the blocks on the links of the upper runsof the lower chains for gripping the lateral portions of the blanksbetween said frictional faces for maintaining the gummed portions of theblanks in substantially taut condition across said space solely by thegripping action on said lateral portions of the blanks while the blanksare being carried through the drying section, and means for deliveringthe blanks in said lapped relation onto said frictional faces of theblocks of the upper runs of the lower chains.

3. Apparatus for conveying envelope blanks in lapped and slightlystepped relation through a drying section of an envelope making machineto expose gummed portions of the blanks to a drying medium, saidapparatus including a lower pair of endless chains each composed ofinterconnected links, blocks of resilient material carried on said linksand having frictional faces for supporting contact with portions of saidblanks laterally of the gummed portions, means for supporting said lowerpair of chains to provide upper runs for continuous movement throughsaid drying section in spaced apart parallel relation and provide asubstantially uninterrupted space between said upper runs at leastcorresponding in width to the width of the gummed portions of the blanksfor the full length of the drying section for access of the dryingmedium to said blanks, separate longitudinal guide means below each ofsaid upper runs for retaining the frictional faces of said blocks inlinear alignment for supporting said lateral portions of the blanksthereupon, an upper pair of endles chains having interconnected links,similar blocks of resilient material on the links of the upper chainsand having frictional faces for pressing contact with the lateralportions of the blanks, means for supporting the upper pair of chains toprovide lower runs in registry with and extending longitudinally abovethe upper runs of the lower chains to operate at the same linear speed,said upper linear runs of the lower chains being of longer length thanthe linear lower runs of the upper chains to project forwardly fromunder linear runs of the lower chains, feed wheels cooperating with theprojecting ends of said upper runs of the lower chains for holding theblanks in position to be engaged by the blocks of the upper chains,guide means for backing said lower runs for pressing the frictionalfaces of said blocks on the links of the lower runs into contact withthe portions of the blanks supported upon the frictional faces of theblocks on the links of the upper runs of the lower chains for grippingthe lateral portions of the blanks between said frictional faces formaintaining the gummed portions of the blanks in substantially tautcondition across said space solely by the gripping action on saidlateral portions of the blanks while the blanks are being carriedthrough the drying section, and means for delivering the blanks in saidlapped relation onto said frictional faces of the blocks at theprojecting ends of the upper runs of the lower chains.

4. Apparatus for conveying envelope blanks in lapped and slightlystepped relation through a drying section of an envelope making machineto expose gummed portions of the blanks to a drying medium, saidapparatus including a lower pair of endless chains each composed ofinterconnected links, blocks of resilient material carried on said linksand having frictional faces for supporting contact with portions of saidblanks laterally and outwardly of the gummed portions, means forsupporting said lower pair of chains to provide upper runs forcontinuous movement through said drying section in laterally spacedapart parallel relation and providing a substantially uninterruptedspace between said upper runs at least corresponding in width to thewidth of the gummed portions of the blanks for the full length of thedrying section for free access of the drying medium to said blanks,separate longitudinal guide means below each of said upper runs forretaining the frictional faces of said blocks in linear alignment forsupporting said lateral portions of the blanks thereupon, an upper pairof endless chains having interconnected links, similar blocks ofresilient material on the links of the upper chains and havingfrictional faces for pressing contact with the lateral portions of theblanks, means for supporting the upper pair of chains to provide lowerruns in registry with and extending longitudinally above the upper runsof the lower chains, said upper runs of the'lower chains being of longerlength than the lower runs of the upper chains to project beyond therespective ends of the lower chains, feed wheels cooperatingrespectively with the projecting ends of said upper runs of the lowerchains for facilitating entrance and exit of the blanks, guide means forbacking said lower runs for pressing the frictional faces of said blockson the links of the lower runs into contact with the portions of theblanks supported upon the frictional faces of the blocks on the links ofthe upper runs of the lower chains for gripping the lateral portions ofthe blanks between said frictional faces for maintaining the gummedportions of the blanks in substantially taut condition across said spacesolely by the gripping action on said lateral portions of the blankwhile the blanks are being carried through the drying section, and meansfor delivering the blanks in said lapped relation onto said frictionalfaces of the blocks at the projecting ends of the upper runs of thelower chains.

Novick Nov. 13, 1956 Daniels et al. Nov. 20, 1956

